Hepcidin
Overview
<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">Hepcidin</th>
</tr>
<tr>
<td class="label">Molecule</td>
<td>Interaction</td>
</tr>
<tr>
<td class="label">[Ferroportin](/proteins/ferroportin-protein)</td>
<td>Direct binding</td>
</tr>
<tr>
<td class="label">IL-6</td>
<td>Induces expression</td>
</tr>
<tr>
<td class="label">BMP6</td>
<td>Induces expression</td>
</tr>
<tr>
<td class="label">HFE</td>
<td>Modulates signaling</td>
</tr>
<tr>
<td class="label">Transferrin receptor 2</td>
<td>Complex formation</td>
</tr>
<tr>
<td class="label">HIF</td>
<td>Represses expression</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">5 edges</a></td>
</tr>
</table>
Hepcidin is a protein. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
Hepcidin is the master regulator of systemic iron homeostasis and a key hormone that controls iron absorption, recycling, and distribution throughout the body. This 25-amino acid peptide hormone directly binds to ferroportin, the sole cellular iron exporter, causing its internalization and degradation.
Structure and Function
Molecular Architecture
...Hepcidin
Overview
<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">Hepcidin</th>
</tr>
<tr>
<td class="label">Molecule</td>
<td>Interaction</td>
</tr>
<tr>
<td class="label">[Ferroportin](/proteins/ferroportin-protein)</td>
<td>Direct binding</td>
</tr>
<tr>
<td class="label">IL-6</td>
<td>Induces expression</td>
</tr>
<tr>
<td class="label">BMP6</td>
<td>Induces expression</td>
</tr>
<tr>
<td class="label">HFE</td>
<td>Modulates signaling</td>
</tr>
<tr>
<td class="label">Transferrin receptor 2</td>
<td>Complex formation</td>
</tr>
<tr>
<td class="label">HIF</td>
<td>Represses expression</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">5 edges</a></td>
</tr>
</table>
Hepcidin is a protein. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
Hepcidin is the master regulator of systemic iron homeostasis and a key hormone that controls iron absorption, recycling, and distribution throughout the body. This 25-amino acid peptide hormone directly binds to ferroportin, the sole cellular iron exporter, causing its internalization and degradation.
Structure and Function
Molecular Architecture
Hepcidin is synthesized as an 84-amino acid prepropeptide that undergoes extensive processing[@krause2000]:
Signal peptide removal: Produces 60-amino acid prohepcidin
Proprotein convertase cleavage: Generates 25-amino acid mature hepcidin
Disulfide bond formation: Creates 4 intramolecular disulfide bondsThe mature peptide adopts a compact hairpin structure stabilized by disulfide bridges between cysteine residues at positions 7-23, 10-13, 11-19, and 14-22[@jordan2023].
Mechanism of Action
Hepcidin acts by binding directly to [ferroportin](/proteins/ferroportin-protein)[@nemeth2004]:
Binding: Hepcidin binds to ferroportin extracellular loop
Internalization: The hepcidin-ferroportin complex is endocytosed
Degradation: Ferroportin is ubiquitinated and degraded in lysosomes
Effect: Cellular iron export is blocked, trapping iron inside cellsRegulation of Hepcidin Expression
Hepcidin expression is regulated by multiple signals[@ganz2011]:
- Iron status: High plasma iron → increased hepcidin (negative feedback)
- Inflammation: IL-6 and other cytokines → increased hepcidin (via STAT3)
- Hypoxia: Low oxygen → decreased hepcidin (via HIF)
- Erythropoiesis: Active red blood cell production → decreased hepcidin
Role in Neurodegeneration
Brain Iron Homeostasis
Hepcidin is expressed in the brain and regulates local iron homeostasis[@raha2013]:
- [Astrocytes](/entities/astrocytes) and [neurons](/entities/neurons) produce hepcidin
- [Blood-brain barrier](/entities/blood-brain-barrier) ferroportin is a target
- Dysregulation leads to brain iron accumulation
- Contributes to neurodegeneration
Neuroinflammation and Hepcidin
Neuroinflammation increases hepcidin expression via IL-6 signaling[@urrutia2013]:
- Chronic inflammation → elevated hepcidin
- Reduced ferroportin → iron retention
- Iron overload in [microglia](/cell-types/microglia-neuroinflammation) and astrocytes
- Enhanced oxidative stress and neuronal damage
Parkinson's Disease
In [Parkinson's disease](/diseases/parkinsons-disease), hepcidin dysregulation contributes to pathology[@wang2020]:
- Elevated hepcidin in substantia nigra
- Decreased ferroportin expression
- Iron accumulation in dopaminergic neurons
- Feed-forward loop of iron-mediated toxicity
Alzheimer's Disease
In [Alzheimer's disease](/diseases/alzheimers-disease), altered hepcidin expression has been observed[@sun2020]:
- Increased hepcidin in affected brain regions
- Iron accumulation around amyloid plaques
- Hepcidin may modulate [Aβ](/proteins/amyloid-beta) aggregation
- Complex relationship with [tau](/proteins/tau) pathology
Ferroptosis Connection
Hepcidin dysregulation promotes [ferroptosis](/mechanisms/ferroptosis)[@stockwell2017]:
- Iron overload → enhanced lipid peroxidation
- Mitochondrial dysfunction
- Reduced glutathione peroxidase 4 (GPX4) activity
- Cell death with characteristic morphological features
Therapeutic Implications
Hepcidin Antagonists
Blocking hepcidin-ferroportin interaction is a therapeutic strategy[@sage2021]:
- Antibodies targeting hepcidin
- Antisense oligonucleotides reducing hepcidin expression
- Small molecule hepcidin receptor antagonists
- May increase iron export and reduce brain iron
Anti-inflammatory Approaches
Reducing inflammation-driven hepcidin elevation[@steinbicker2013]:
- IL-6 receptor antagonists (tocilizumab)
- JAK/STAT pathway inhibitors
- May normalize hepcidin levels
- Potential benefit in neurodegeneration
Clinical Trials
Several hepcidin-targeting agents are in development[@kautz2014]:
- LY2787106 (anti-hepcidin antibody)
- NOX-H94 (anti-hepcidin spiegelmer)
- PTS-107 (hepcidin inhibitor)
- Applications include anemia of chronic disease
Diagnostic Applications
Biomarker Potential
Hepcidin levels may serve as biomarkers[@kroot2011]:
- Serum hepcidin reflects systemic iron status
- CSF hepcidin may indicate brain iron dysregulation
- Could predict response to iron chelation therapy
- May track disease progression
Measuring Hepcidin
Methods for hepcidin measurement include[@kroot2009]:
- Mass spectrometry-based assays
- ELISA immunoassays
- Challenges due to peptide stability
- Standardization across laboratories needed
Interactions with Other Molecules
Research Directions
Current research focuses on[@vela2019]:
Brain-specific hepcidin regulation
Hepcidin antagonists for neurodegeneration
Combination with iron chelation therapy
Biomarker development
Neuroinflammation-hepcidin interactions
Hepcidin-[ferroptosis](/entities/ferroptosis) connectionsSee Also
- [Parkinson's disease](/diseases/parkinsons-disease)
- [Alzheimer's disease](/diseases/alzheimers-disease)
- [ferroptosis](/mechanisms/ferroptosis)
External Links
- [PubMed](https://pubmed.ncbi.nlm.nih.gov/)
- [KEGG Pathways](https://www.genome.jp/kegg/pathway.html)
References
[Krause A et al, LEAP-1, a novel highly disulfide-bonded human peptide, exhibits antimicrobial activity (2000)](https://pubmed.ncbi.nlm.nih.gov/10748062/)
[Jordan JB et al, Structural basis for hepcidin-mediated inhibition of ferroportin (2023)](https://pubmed.ncbi.nlm.nih.gov/37620901/)
[Nemeth E et al, Hepcidin regulates cellular iron efflux by binding to ferroportin and inducing its internalization (2004)](https://pubmed.ncbi.nlm.nih.gov/14985369/)
[Ganz T, Hepcidin and iron regulation, 10 years later (2011)](https://pubmed.ncbi.nlm.nih.gov/21768341/)
[Raha AA et al, Hepcidin, ferroportin and brain iron homeostasis (2013)](https://pubmed.ncbi.nlm.nih.gov/24424461/)
[Urrutia P et al, Inflammation alters the expression of DMT1, FPN1 and hepcidin, and it causes iron accumulation in central nervous system cells (2013)](https://pubmed.ncbi.nlm.nih.gov/24681152/)
[Wang J et al, Increased hepcidin expression in the substantia nigra of Parkinson's disease patients (2020)](https://pubmed.ncbi.nlm.nih.gov/31735939/)
[Sun J et al, Hepcidin as a key player in the pathogenesis of Alzheimer's disease (2020)](https://pubmed.ncbi.nlm.nih.gov/33279485/)
[Stockwell BR et al, Ferroptosis: A Regulated Cell Death Nexus Linking Metabolism, Redox Biology, and Disease (2017)](https://pubmed.ncbi.nlm.nih.gov/28132922/)
[Sage D et al, Hepcidin antagonists for therapeutic use (2021)](https://pubmed.ncbi.nlm.nih.gov/34025198/)
[Steinbicker AU, Mückenthaler MU, Out of balance—systemic iron homeostasis in inflammation (2013)](https://pubmed.ncbi.nlm.nih.gov/23719328/)
[Kautz L, Nemeth E, Molecular liaisons between erythropoiesis and iron metabolism (2014)](https://pubmed.ncbi.nlm.nih.gov/24908389/)
[Kroot JJC et al, Hepcidin in human iron disorders: diagnostic implications (2011)](https://pubmed.ncbi.nlm.nih.gov/21860058/)
[Kroot JJC et al, (Pre)analytical imprecision, standardization, and biological variation of human plasma hepcidin assays (2009)](https://pubmed.ncbi.nlm.nih.gov/19657119/)
[Vela D, Hepcidin, the missing link between inflammation and anemia in chronic disease (2019)](https://pubmed.ncbi.nlm.nih.gov/30905901/)Pathway Diagram
The following diagram shows the key molecular relationships involving Hepcidin discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)